1. Field of the Invention
The present invention relates to a method for producing reticular nonwoven fabric. More particularly, the invention relates to a method for continuously producing the reticular nonwoven fabric in which a longitudinally oriented reticular first film material is laminated with a transversely oriented reticular second film material.
2. Description of the Prior Art
A production method of this kind is described in Japanese Patent Publication No. 1-53383. This method comprises a continuous process of a longitudinal line step to form a longitudinal web, a transversal line step to form a transversal web and a laminating step to laminate the longitudinal web and the transversal web. The longitudinal line step comprises a continuous process of a film feeding step to feed a nonstretched film in the form of a continuous web, a transversely slitting step to form a number of transversal slits at small regular intervals in view of longitudinal direction, and a transversely stretching step to stretch transversely this transversely slit nonstretched film. Meanwhile, the transversal line step comprises a continuous process of a film feeding step to feed a non-stretched film in the form of a continuous web, a longitudinally slitting step to form a number of longitudinal slits at small regular intervals in view of transversal direction, and a longitudinally stretching step to stretch longitudinally this longitudinally slit nonstretched film.
In the longitudinal line step of this method, because the film is stretched in the longitudinal direction, the discharging velocity of the film is larger than the feeding velocity of the film. In the transversal line step, however, the velocity of feeding of film is the same as that of the discharging of film because the film is not stretched in the longitudinal direction but it is stretched in the transversal direction. The velocity of the whole line depends on the velocity of the transversal line because the velocities of both films must be made the same in the laminating step. Due to this reason, the method is not advantageous in view of the rate of production.